1. Field of the Invention
This invention relates to a device for use with a telephone system for generating dialing signals representative of any one of a plurality of telephone numbers stored in digital registers and more particularly, to such a device which employs a plurality of number selection keys which is an integral divisor of the number of telephone numbers that may be stored in the device.
2. Prior Art
For the convenience of telephone users a variety of automatic dialing devices have been developed which allow the user to encode a limited number of frequently employed telephone numbers. When the user wants to dial one of these stored numbers, he simply moves the selector to a position which selects the desired number and then presses a button, or alternatively presses one of a number of buttons, each associated with a different stored telephone number. The device automatically generates the dialing pulses or tones for the encoded number and transmits them over a connected telephone line. The units typically incorporate a keyboard or the like for the use by the operator in storing a number, or altering a previously stored number, as well as a graphic list of the stored numbers, or the names of the parties associated with particular numbers, which are altered when the stored numbers are altered.
Most of these automatic dialing devices fall into one of two types, depending upon whether they store the telephone number codes in magnetic form or digital registers. One type, magnetically coded devices, often employ a magnetic belt, rotatably supported with respect to the device housing so that the operator may move the belt to bring a particular position on the belt, which carries a graphic display of a desired telephone number, into position with a viewing window. This action simultaneously brings a section of the belt which carries a magnetic code for the same telephone number into position with a magnetic reading head. The number viewed through the window may then be dialed by depressing a button which causes the magnetic head to read code signals for the number and provide them to a dial signal generator.
An alternative form of automatic dialer incorporates a number of digital storage registers, each adapted to store the codes for a single telephone number. Each register has a pushbutton connected to it and graphic display areas, each associated with buttons, may be marked with the telephone number encoded in the associated digital register. To dial a particular number the operator merely presses the button next to the graphic display of the desired phone number to provide the contents of the associated register to a dial signal generator.
This digital register type of automatic dialer is mechanically simpler than the magnetic type and is more reliable in operation, but it suffers from the disadvantage of requiring a large number of pushbuttons, one for each phone number stored in the device. The large number of buttons adds to the manufacturing cost of the device and effectively limits the number of phone numbers that may be stored in a device of a given size without so crowding the buttons as to make selection of a particular number difficult.
The present invention is accordingly directed toward a telephone dialer which enjoys the advantages of the digital register type unit, but does not require a single button for each number stored in the machine, allowing the design of a relatively compact, high capacity dialing device.